Brief Summary

Overview

Ants, are classified in the family Formicidae. These insects are native to nearly all terrestrial habitats and all parts of the globe except for Antarctica, Iceland, Greenland, some parts of Polynesia, and a few remote Indian Ocean and Atlantic Ocean islands(3), and are often extremely abundant locally(2). Though there are over 8,800 species known (and perhaps over 11,000 more that have not been described)(3), ants generally have a distinctive body structure: while they have, like many insects, a head, thorax (the midsection), and abdomen (the rear section), their “waist” connecting their thorax to the main part of their abdomen is unusually thin and pinched (1,3). Most ants are also characterized by the presence of a metapleural gland, an organ that produces a chemical called phenylacetic acid that is used for fighting bacteria and fungi(2,3); this gland may have helped ants colonize the moist environments where most ant species now live(2). Like only a few other groups of insects, ants have evolved a complex system of social interaction that qualifies them as “eusocial” insects(2,3). They live and work together in multi-generational colonies that are generally organized in “castes” of queens and males (who reproduce) and worker females (who cannot reproduce)(2,3), communicating via a chemical communication system that may be more complicated than that of any other kind of animal(2). In addition to these extraordinary social structures, ants have complex and extremely important relationships with many other species, giving them a central role in ecosystems across the globe(2). Some ants have partnerships with fungi(2). Some ants defend plants from herbivores, help plants reproduce by pollinating their flowers and spreading their seeds, and help plants grow by turning over the soil (which keeps it rich and healthy)(1,2,3). In fact, many plants depend on ants for their survival(3). On the other hand, some ants are the primary plant-eaters in their environments(1,2), and in many cases ants are major predators of small animals(2). Although some ant species can be pests themselves(1,2), some are beneficial to humans by feeding on harmful crop pests(2)—and by serving as subjects for a wide range of scientific studies(2,3).